1. Field of the Invention
The present invention relates to the field of wagon technology.
2. Description of the Background Art
Wagons are a traditionally and widely used form of transportation. Wagons are used to carry a wide variety of goods, including grains, livestock, dry goods, persons, liquids, machinery, etc.
Wagons in their most basic form include a tongue, a frame, at least one pair of wheels, and a bed, box, or tank for hauling cargo. The tongue of the wagon may be connected to a vehicle, such as, for example, a tractor, truck, pickup harvester, or other self-propelled machine. A variety of wheels may be used, depending on the intended use.
A common variation is the four-wheeled wagon, having pairs of wheels at either end of the wagon. The extra pair of wheels contribute to stability of the wagon and may also increase the load-carrying capacity. In a four-wheeled wagon, generally one pair of steerable wheels is capable of being pivoted in unison so that the wagon may be turned. The turning action is controlled by the tongue, which pivots the steerable wheels (i.e., the front wheels) by means of a steering rod or rods which connect the tongue to each steerable wheel. As the tongue is displaced to either side of a center position, both steerable wheels are therefore pivoted.
In a conventional wagon construction, a frame is employed upon which the pairs of wheels are mounted. The tongue is pivotally attached to the front of the frame and connected to the steerable wheels through a steering linkage. The wheels and corresponding axles extend beyond the frame, but are positioned relatively near to the frame. This is because if the wheels extended far beyond the frame, excessive bending loads would be imposed on the axles, with possible breakage occurring as a result of heavy loads or due to traveling over rough roads or rough ground. Conventional wagon designs therefore have a frame positioned generally within about one-half of the wheel diameter from the wheel.
A steerable wheel mounted close to the wagon frame has a drawback. The proximity of the frame limits the ability of the steerable wheels to pivot, and thereby limits the turning radius of the wagon. Turning ability is therefore limited in either direction.
What is needed therefore is a wagon having improved turning ability without positioning the steerable wheels farther from the wagon frame.